Viagen, Inc., Suite 100, Austin, TX 78727, USA.
Theriogenology. 2010 Jul 1;74(1):1-10. doi: 10.1016/j.theriogenology.2009.12.013. Epub 2010 Feb 25.
The objective was to assess the risk of transmission of bovine viral diarrhea virus (BVDV) through embryo production via somatic cell nuclear transfer (SCNT), with oocytes obtained from persistently infected (PI) donors. Using ultrasound-guided follicular aspiration following superstimulation, oocytes were obtained from five female beef cattle, including three that were PI and two that were negative for BVDV. In the three PI cattle, seven aspirations yielded 32 oocytes (PI-1: three aspirations yielding six oocytes; PI-2: two aspirations yielding 14 oocytes; and PI-3: two aspirations yielding 12 oocytes). The oocyte recovery rate was better in negative control cattle, with 32 oocytes obtained from the two cattle in a single superstimulation and aspiration session. Oocytes were processed individually for SCNT, evaluated, and tested for BVDV. Nearly all (31/32) oocytes from the three PI donors were positive for BVDV by PCR, with detected viral RNA copy number ranging from 1 to 1.1 x 10(5). The proportion of oocytes acceptable for SCNT embryo production (based on oocyte quality and maturation status) was only 16 to 35% from PI donors, but was 81% from control donors. Therefore, routine testing of unacceptable (discarded) oocytes could be an effective approach to identify batches that might contain infected oocytes from PI donors. Identification and removal of high-risk batches of oocytes would minimize the risk of BVDV transmission through SCNT embryo production.
本研究旨在评估通过体细胞核移植（SCNT）生产胚胎时，来源于持续性感染（PI）供体的卵母细胞传播牛病毒性腹泻病毒（BVDV）的风险。通过超数排卵后的超声引导卵泡抽吸，从五头肉牛中获得卵母细胞，其中三头为 PI，两头为 BVDV 阴性。在这三头 PI 牛中，七次抽吸获得 32 个卵母细胞（PI-1：三次抽吸获得 6 个卵母细胞；PI-2：两次抽吸获得 14 个卵母细胞；PI-3：两次抽吸获得 12 个卵母细胞）。阴性对照牛的卵母细胞回收率更好，单次超数排卵和抽吸即可获得 32 个卵母细胞。对卵母细胞进行单独的 SCNT 处理、评估，并进行 BVDV 检测。来自三个 PI 供体的几乎所有（31/32）卵母细胞均通过 PCR 检测为 BVDV 阳性，检测到的病毒 RNA 拷贝数范围为 1 至 1.1 x 10(5)。PI 供体的卵母细胞可用于 SCNT 胚胎生产的比例（基于卵母细胞质量和成熟状态）仅为 16%至 35%，而对照供体的比例为 81%。因此，对不可接受（丢弃）的卵母细胞进行常规检测可能是一种有效方法，可以识别出可能含有 PI 供体感染卵母细胞的批次。鉴定和去除高风险批次的卵母细胞可以最大限度地降低通过 SCNT 胚胎生产传播 BVDV 的风险。
